GPS Bouncing

[+GorpForBrains]

Hi Groundspeak community! First time poster and new geocacher.

 

My wife and I are looking for a little advice on using our Garmin eTrex Vista HCx.

 

We're noobie geoacachers and have found 8 caches on 3 hunting trips with a bunch of DNF's including 2 locations which we've taken multiple trips to try to find. We're having a lot of fun, but want to improve our usage of our new GPS unit which we cache with. Sometimes we have no problem at all finding our cache locations (then it's just the fun of finding the cache) with only about a 6 foot differential on position to cache. Sometimes the GPS bounces around as much as 50 feet in random crazy directions.

 

I've read a bunch of the manual, but hey I'm a tech geek and don't want to read through every page of the manual to find the 1 or 2 lines of text which might help me with this problem (if there's even that level of detail in the little manual).

 

We have the US West National Parks and North West TOPO 24K so we got good, detailed maps.

We sync directly to the GPS from the search pages on geocaching.com.

We've tried calibrating the compass.

We've tried turning off / on the GPS when we're "near the cache" to make sure the satellite get a good positon on us.

 

Any advice works well.

Edited January 28, 2010 by GorpForBrains

[+Gitchee-Gummee]

First and foremost: Do not expect it to put you atop the cache. Generally, ground zero (GZ) is accepted to be a ±20' radii circle in the "area" of the cache. You know this is a hunting game, and you still have to hunt!

 

Couple your ±20' with the same from the placement coords, you could easily be considering a circle of more than 40' to be ground zero.

 

When you are moving very slowly, or wandering about in circles (especially under cover or around buildings), you must expect signal bounce. When close to the cache, simply turn the unit off, put it in your pocket, and think "Now just where would I hide it (the cache)?"

 

EDIT: Don't know how "n00b" you are, but if you have less than 10 finds, avoid the small and micros for the time being. Work mostly larger caches to gain that hunting experience.

 

Have fun.

Edited January 28, 2010 by Gitchee-Gummee

[+briansnat]

What you are experiencing is normal. Multi pathing errors (AKA signal bounce) can give you weird readings and make it difficult for the hider to obtain good coords.

 

Make sure your Vista's compass is calibrated if you are experiencing odd readings (it should be calibrated every time you change batteries and sometimes if it has been sitting unused for a while). If it is, then there is little more you can do.

 

Finding caches 50 or more feet from where your GPS says it should be is not unheard of, though most will be within the 10-30 ft range.

Edited January 28, 2010 by briansnat

[Rocketsteve]

I have a Vista HCx and I've looked for and found caches that were better than 30 feet from where my GPSr said it was supposed to be. If the Cache Owner doesn't have a high-sensativity antenna GPSr, any overhead cover (i.e. tress) will notably impact the accuracy of the cache coordinates. Basically, I use my Vista to get me within 15 - 20 feet of the cache, and then I let my geo-senses take over. Unless I'm having a really bad day, I can usually find the cache within 10 minutes of walking into GZ.

[+StarBrand]

The general accuracy of most handheld GPS devices is around 15 to 25 feet. Remember though you have might have to add your potential error to any error the cache owner had when placing the cache. That means you could easily find yourself looking for a cache up to 50 feet (roughly) from where your unit says ground zero is. Most of the time you will find them within 20 feet or less but do be prepared to widen your search area. Put the GPS away when you are within 20 feet or so and start looking for likely hiding spots.

 

Back off and re-approach the area if necessary to verify you are looking in the right spot. Beaware that some large objects with smooth flat surfaces nearby can create addtional errors that are hard to correct for (multipath).

[+GorpForBrains]

Don't know how "n00b" you are, but if you have less than 10 finds, avoid the small and micros for the time being. Work mostly larger caches to gain that hunting experience.

 

We're currently at 8 finds. 3 micro, 1 small, 4 regular. So yeah our "geo-sense" isn't quite honed yet and pretty much every cache we've found has been hidden in a way that's surprised us. Some of the caches we've been stumped by have been "regular" sized caches with a 1.5 difficulty though which is what had me worried I was doing something wrong with the GPS. I didn't expect it to be 100% right on every time of course. I just wanted to know if I was doing things right which it sounds like I have been.

 

Thanks for all the tips, I wasn't sure how often I needed to calibrate my compass for example.

Edited January 29, 2010 by GorpForBrains

[+Gitchee-Gummee]

Don't worry so much about being stumped. Truly.

 

We know cachers with 1,000s of finds that still DNF here and there. Is just a matter of life.

 

Do you fish? How often do you catch them all?

 

How often do you catch none?

[knowschad]

First of all, I love the name of your town! "Happy Valley, Oregon"

 

Valleys (or perhaps I should say, "ravines") in particular are infamous for "bounce". I don't know the technical reason for it, but I've been caching long enough to see it repeatedly. And as has been pointed out earlier, if you are experiencing it, odds are good that the hider was, as well.

 

I sometimes have to recalculate the compass on my GPSMap 60CSX at times when I have been out cacheing, have not changed the batteries or any of that. I'll just notice that it isn't acting right... maybe pointing in an obviously wrong direction, yet the distance increasing as I head that way, instead of decreasing.

[Rocketsteve]

Don't know how "n00b" you are, but if you have less than 10 finds, avoid the small and micros for the time being. Work mostly larger caches to gain that hunting experience.

 

We're currently at 8 finds. 3 micro, 1 small, 4 regular. So yeah our "geo-sense" isn't quite honed yet and pretty much every cache we've found has been hidden in a way that's surprised us. Some of the caches we've been stumped by have been "regular" sized caches with a 1.5 difficulty though which is what had me worried I was doing something wrong with the GPS. I didn't expect it to be 100% right on every time of course. I just wanted to know if I was doing things right which it sounds like I have been.

 

Thanks for all the tips, I wasn't sure how often I needed to calibrate my compass for example.

 

Personally, I like to re-calibrate my compass just before I start caching that day, and in the event something happens to my GPSr, I also carry a "real" compass as a backup.